An evaluation of oral hexoprenaline sulphate (Ipradol) in exercise-induced asthma

The effect of hexoprenaline sulphate (1 mg) administered orally on the fall in peak expiratory flow rate (PEFR) after exercise was investigated in 20 asthmatic patients. Compared with placebo, the fall in PEFR expressed as a percentage of the resting value (measured immediately before exercise) was less in 16 of the 20 patients in the presence of hexoprenaline sulphate. This consistent amelioration of exercise-induced asthma has not been observed in this laboratory with similar drugs (such as salbutamol and terbutaline). While eight patients were afforded significant protection by the hexoprenaline sulphate, a fall in PEFR after exercise was within the normal range (less than 10% of the resting value) in only four patients.